Valve system



Feb. 2, 1943. THUWM ETAL 2,310,130

VALVE SYSTEM Original Filed Feb. 6, 1940 .Il MM E@ MINIT- inventors:Carl Thumm, Edward J. Frank,

AI exancie^ C. Boisseau,

DE @M75-14M@ A'Ihei r Attomeg.

Patented Feb. 2, 1943 VALVE SYSTEM Carl Thumim and Edward J. Frank,Yeadon, and

Alexander G. Boisseau, Lansdowne, Pa., assignors to General ElectricCompany, a corporation of New York Original application February 6,1940, Serial No. 317,564. Divided and this application July 16,

1940, Serial No. 345,810

1 claim. (ci. 137-129) Our invention relates to valve systems and moreparticularly to valve systems for the control of the flow of gas underpressure such as is used in connection with gas-blast circuit breakers.

This application is a division of our application Serial No. 317,564,led February 6, 1940, entitled Circuit breaker operating system andassigned to the same assignee as the present invention,

In order to eliminate the lire hazard, circuit breakers have beendesigned which do not utilize oil or other inflammable liquid forarc-extinguishing purposes but instead employ a blast of air or othergas to extinguish the arc formed both when the circuit is broken betweenthe relatively movable contacts of the circuit breaker and also duringthe closing operation of the circuit breaker to prevent the formation ofany arc at this time. Apart from numerous operating and structuraladvantages of gas-blast circuit breakers for many applications, theproblem of providing a suitable control or operating system furnishesconsiderable diiculty.

The value of any circuit breaker lies in its ability to linterrupt thecircuit at the proper time and in the proper manner and without a properoperating system for such circuit breaker, its value is largely lostsince the value of the operating system lies in its ability to effectcontrol of the circuit breaker in the manner intended. If such controlis not obtained in the manner desired, many undesirable conditions mayresult.

It is necessary to obtain opening of the circuit breaker in as short atime as possible after the condition which initiates the openingmovement occurs and this is no less true of gas-blast circuit breakersthan of any other type. In order to produce the gas-blast, a valve mustbe operated releasing the fluid under pressure at the proper instant. Tooperate such a valve directly against the fluid pressure would requireconsiderable force and, in addition, would tend to slow down theoperating cycle of the circuit breaker.

Balanced pressure valves have been proposed for this purpose, wherein apilot valve requiring relatively little force to operate, unbalances thepressure on a piston-operated valve so that the fluid pressure forcesthe blast valve open. The balanced pressure valves of the prior art didnot operate with the speed desired for high-speed circuit breakeroperation and gas-blast circuit be desired. We have provided a new andimproved operating system for gas-blast circuit breakers including abalanced pressure type of blast valve which operatesat a much higherspeed than the balanced pressure valves of the prior art.

breaker operating systems employing balanced Accordingly, it is anobject of our invention to provide a new and improved blast valve forcontrolling the flow of uid.

It is another object of our invention to provide a new and improvedvalve system in which a small operating force may control a relativelylarge valve operating it at high speed.

Further objects and advantages of our invention will become apparent asthe following description proceeds and the features of novelty whichcharacterize our invention will be pointed out with particularity in theclaim annexed to and forming a part of this specification.

For a better understanding of our invention,

-reference may be had to the accompanying drawing in which Fig. 1 is across-sectional View of the blast valve of our invention, and Fig. 2

is a sectional view taken on line 2-2 of Fig. l.

Referring now to the drawing, we have illustrated blast valve 56 ascontrolling the flow of 5l which is mounted in a casing 59 enclosing acylinder 6l within which piston 60 operatively connected to valve member5l reciprocates. Piston 60 is preferably exibly connected with valvemember 51 for the purpose of self-alignment and is provided with a valveguide 62 reciprocating in a sleevelike member 63. A spring member 613 isplaced between sleeve member 63 and valveY member 5l normally to tend tohold said valve member in the closed position. Cylinder 6i, sleevelikemember 63, and spring member 64 are supported centrally by radial ribs65 bridging across annular air passage 53. Y

The upper end of cylinderV 6i is closed by a plate 66 to which isfastened a metallic striking plate 6l. Between the metallic strikingplate 6l and plate 66 is a flexible bulier disk 68 to cushion theopening of blast valve 56. The space 69 in cylinder 6l between piston 60and striking plate 51 is maintained at the absolute minimum determinedonly by the space required for opening valve 51 as will be set forth ingreater detail hereinafter. A small passage is provided in piston 69 tointerconnect the cylinder 6| on either side of piston 69 and, hence, tobalance the pressures operating on the upper and lower surfaces understeady-state conditions. The area of piston 6B is relatively largecompared to the area of Valve member 51 so that a considerably lowerpressure operating on piston 69 may overcome a higher pressure operatingon valve member 51.

In order to open blast valve 55, a pilot Valve 1| of relatively largediameter is opened, rapidly releasing the pressure on the upper side ofpiston 69, whereby an unbalance of the pressure on piston 88 is obtainedand the fluid pressure operating against the under side of piston 60 issufficient to overcome the forces holding valve member 51 closed, whichcomprise the uid pressure acting on the back of valve member 51 andspring means (Se. Thereupon valve member 51 is forced open rapidly andpiston 69 contacts with striking plate |51 whereupon check valve 12closing port 13 in piston 69 is opened by virtue of the extension 14thereon which engages with striking plate @1. The upper surface ofpiston 69 is recessed at 15 so that fluid pressure either through smallpassage 19 or port 13 within which check valve 12 operates isdistributed over the entire upper surface of piston 60.

The time of opening of valve 51 is dependent upon the rate of pressuredrop in space 69 which, in turn is a function of the volume of space 69and the area of pilot valve 1|. In the balanced pressure valves of theprior art, the volume of space 69 was necessarily large to accommodatethe biasing spring which was contained in this space. By eliminatingspring 64 from space 69, it has been possible to decrease greatly thevolurne of space 69 determined only by the clearance necessary for valvemember 51. Furthermore, the area of pilot valve 1| hasbeen made as largeas practicable and this combination has v enabled us to obtain anoperating speed much higher than was possible heretofore.

Check valve 12 is provided so that pressure in space 99 may be built uprapidly when pilot valve 1| is closed so that valve member 51 is snappedshut in a minimum period of time. The extension 1li on check valve 12 issuilciently long so that check valve 12 is maintained in the openposition for a reasonable length of time -to prevent uttering of thevalve member 51.

It will be understood by those skilled in the art' that operation ofpilot valve 1| requires considerably less opera-ting force than would berequired to open blast valve 51 directly. The pilot valve il andoperating mechanism 16 therefor are mounted as a complete constructionalunit in U-shaped frame members 11 and 18 which are bolted at 19 and 80,respectively, to casing 59. PilotI Valve 1| is held in the closedposition by means of spring mechanism 8| supported by U- shaped memberi8 and including adjustable means B2 by which the closing force on pilotvalve 1l may be adjusted to just overcome the normal iiuid pressure inspace 69 tending to open pilot valve 1l. Movement of pilot valve 1|against the force of spring mechanism 8| is effected through a pair oflevers 83 pivotally mounted at 84 to U-shaped member 11 andinterconnected by block S5 provided with an opening 8G through which rod81 for operating pilot valve 1| is connected. This opening 86 in block85 is enlarged at either end thereof so as to prevent any binding actionbetween rod 81 and block 85 during the pivotal movement of levers 83.Pivotal movement of levers 83 is obtained either by the leftward pull ofarmature 88 of solenoid 89 or by the leftward thrust of armature 90 ofsolenoid 9|. Pivotally mounted levers 83 are connected in clevislikefashion to armature 88 at 92 while an extension 93 provided with aroller 94 is connected to armature 90 of solenoid 9| so that movement ofarmature 9U may be transmitted through roller 94 and armature 88 topivotally mounted members 83 for operating pilot valve 1|. solenoids 89and 9| are coaxially mounted and connected to one another by means of U-shaped plates 95. The entire apparatus including solenoids 89 and 9| issupported from casing 59 as a unitary structure by member 96.

Pivotally mounted levers 83 may be provided with a roller 91 foroperating a suitable switch 98, biased to the closed position by springmeans 99, whenever pilot valve 1| is opened.

The operation of balanced pressure valve 58 will be obvious to thoseskilled in the art in View of the detailed description included above.if either solenoid 89 or 9| is energized, levers 83 are rotated so as toopen pilot valve 1| against the bias of spring means 8i. Such openingrof pilot valve 1| will allow the pressure in space 69 to decreaserapidly so that the pressure balance on piston 60 is disturbed and theforce acting upwardly on piston 68 being very large with respect to thedownwardly acting forces causes opening of valve member 51 so that ablast of iiuid may flow from conduit 21 through annular passageway 5S toconduit l5. As long as pilot valve 1| is open, the relatively largediameter thereof allows any fluid passing through small opening 19 toescape, thereby maintaining an unbalanced pressure on piston 69 so thatvalve member 51 remains in its open position.

Because of the sudden unbalance of pressures on piston B9 when pilotvalve El is open, valve member 51 opens at very high speed and piston6|] engages with resiliently supported striking plate 61. Extension 14of check valve v'l2 engages with striking plate 81 and causes opening ofthis valve but, aslong as pilot valve 1| is open, insuicient fluidpressure is allowed to pass to the upper end of cylinder 6| so thatvalve member 51 is held in the open position by the unbalanced fluidpressures. Upon deenergization of either of the solenoids S9 or 9|,pilot valve 1l will snap shut under the force of spring means 8| and thevery small volume 69 above piston (il) is rapidly filled with uidthrough opening 19 and check valve 12. As soon as sufficient pressure isbuilt up therein, valve member 51 is snapped shut, thereby cutting offcommunication between con duits 21 and l5. From the above description,it will be observed that a relatively small force is required to openpilot valve 1|, which causes operation of balanced pressure valve 56against the high fluid pressures whichare controlled by valve 56.

Although we have described our invention as usable in connection with agas-blast circuit breaker, it will be understood by those skilled in theart that it is applicable to any arrangement where it is desired tocontrol the flow of fluid under pressure to a lower pressure region.

It will be apparent to these skilled in the art that our invention isnot limited to the particular 4construction shown but that changes andmodifications may be made Without departing from the spirit and scope ofour invention and We aim in the appended claim to cover all suchchangesV and modifications.

What We claim as new and desire to secure by Letters Patent of theUnited States is:

A valve system comprising a. main valve member for controlling the ow ofuid between a source of uid under pressure and a fluid passage, a pistonoperatively connected to said main valve member, a cylinder for saidpiston, means for closing one end of said cylinder to define a chamberin said cylinder having a minimum volume determined solely by theopening movement of said main valve member, said piston and cylinderbeing so constructed and arranged that the forces acting on said pistondue to fluid under pressure are substantially neutralized during theclosed position of said valve, a solenoid-operated pilot valve forsubstantially instantaneously releasing the fluid under pressure injsaidchamber to unbalance the forces acting on :said piston and causehigh-speed opening of said? valve, means for limiting and cushioning theVopening movement of said valve, and a checkvalve in said pistonarranged to engage with vsaid last-mentioned means to cause openingthereof when said main valve is in the open position, whereby high-speedclosing of said main valve is obtained upon closing of said pilot valve.

CARL THUMIM. EDWARD J. ALEXANDER C. BOISSEAU.

